The present invention relates to a control system of an automatic vending machine and more particularly, to a control circuit to be controlled by microcomputers for the controlling operation of an automatic vending machine.
In recent years, the application of the microcomputers to the automatic vending machines is actively performed not only to greatly contribute towards the function improvements, but also to deal with various problems. In the automatic vending machine, the control circuit has to perform the actions such as inserted money-amount operation, balance operation after the sales, no-changes detection, commodity sell-out detection, sold-out commodity display, purchasable commodity decision, purchasable commodity display, commodity-selection-switch-action detection, commodity delivery, change payment, etc. However, the control circuit under the control of the conventional microcomputers is often connected, one to one, with the terminal apparatuses such as switch apparatus, driving apparatus, display apparatus. When one microcomputer of the control circuit directly controls each of the terminal apparatuses concentrically, the following defects are caused due to the concentration of the functions upon the control circuit.
(1) Assembling operation efficiency;
The operation efficiency in the assembling process is inferior due to the increased number of the base-plate components of the control circuit unit. The increased defect factor implies the analysis of the defect caused and the repair to be difficult to be performed. Also, as signal wires from the control circuit increase in number, the problems of wiring disposal and error wiring increase.
(2) Design efficiency;
The base plates of the control circuit unit are required to be individually designed with respect to each of the automatic vending machines. Also, the hardwares and the softwares thereof are becoming complicated due to multiple functions. Particularly, the softwares have problems in their work assignments, thus resulting in heavy loads on the software engineers, and requirement of more time for development and debugging.
(3) Service;
The control circuit becomes so large that the repairing operation is difficult to be effected, with the result that the service cost becomes higher.
In the U.S. Pat. No. 4,267,915, data bus bars and a multiplex system are adopted in the circuit construction, which introduces the price data of the sales commodity to the control circuit. The idea of such bus bars and multiplex is applied even to the other signal system of the automatic vending machine so that increase in the number of the wirings can be coped with to some extent. However, in the U.S. Pat. No. 4,267,915, the data bus bars and the multiplex do not result in the effective number reduction of the wirings, because the data are transmitted in parallel. In the many uses of the multiplex system in the signal system, the transmission and reception of signals are hardly performed one to one between the control circuit and each of the terminal apparatuses. When something unusual has happened, it becomes difficult to analyze which terminal apparatus is wrong or whether or not the control circuit is wrong. Thus, inconveniences on the service increase. Also, in the effective reduction of the number of the wirings, the serial transmission of the data between the control circuit and each terminal is disclosed in the Japanese Patent Publication (Tokkosho) No. 58-16230. However, in the Japanese Patent Publication (Tokkosho) No. 58-16230, the number of the wirings can be effectively reduced, but the function concentration on the control circuit remains unsolved. The defects are difficult to be analyzed, and problems remain in terms of assembling operation, design efficiency, service.